Mixed phases of sphene structure

ABSTRACT

Synthetic mixed phases of sphene structure corresponding to the general formula MMeZX5 or MMeZX4Y and comprising as host components pure or isotype mixed phases in which M calcium and/or barium, Me titanium and/or tin, Z silicon, X oxygen and Y fluorine and/or hydroxyl, comprising at least about 0.1 percent by weight of at least one guest component in place of the aforementioned host components without any change in the sphene structure or in the electroneutrality, the guest component for Z being a di-valent to pentavalent cation with an ionic radius of less than about 0.6 A. and/or a zinc cation, for Me being a monoto hexavalent cation with a radius of from about 0.45 A. to about 1.0 A. and for M being a mono-to tetra-valent cation with a radius of greater than about 0.9 A., the stoichiometric quantities for (Me+M):Z:(X+Y) being about 2:1:5.

[ Aug. 21, 1973 MIXED PHASES OF SPHENE STRUCTURE [75] Inventor: Franz Hund,KrefeId-Bockum,

Germany [73] Assignee: Bayer Aktiengesellschaft,

Leverkusen, Germany [22] Filed: July 27, 1971 [21] App]. No.: 166,374

[30] Foreign Application Priority Data July 31, 1970 Germany P 20 38 007.8

[52] U.S. Cl 106/288 B [51] Int. Cl. C09c [58] Field of Search 106/288 13, 299

[56] References Cited UNITED STATES PATENTS 3,022,186 2/1962 Hund 106/288 B 3,091,544 5/1963 Hund et a1. 106/288 B 3,249,398 5/1966 Bayer..... 106/288 B 3,424,551 1/1969 Owen 106/299 X FOREIGN PATENTS OR APPLICATIONS 1,361,074 4/1964 France 106/288 B 1,417,251 11/1968 Germany 106/288 B OTHER PUBLICATIONS Mellor, A Comprehensive Treatise On Inorganic and Theoretical Chemistry, Longmens Green & Co., N.Y., V0]. 6, PP. 839-859 (1925).

Primary Exqminer-l-lelen M. S. Sneed Attorney-Ralph D. Dinklage and Arnold Sprung et [57] ABSTRACT Synthetic mixed phases of sphene structure corresponding to the general formula MMeZX, or MMeZX Y and comprising as host components pure or isotype mixed phases in which M calcium and/or barium, Me titanium and/0r tin, Z silicon, X oxygen and Y fluorine and/or hydroxyl, comprising at least about 0.1 percent by weight of at least one guest component in place of the aforementioned host compo nents without any change in the sphene structure or in the electroneutrality, the guest component for Z being a di-valent to pentavalent cation with an ionic radius of less than about 0.6 A. and/or a zinc cation, for Me being a monoto hexavalent cation with a radius of from about 0.45 A. to about 1.0 A. and for M being a mono-to tetra-valent cation with. a radius of greater than about 0.9 A., the stoichiometric quantities for (Me+M):Z:(X+Y) being about 221:5.

6 Claims, 4 Drawing Figures PATENIEDMIB21 I975 sum 1 0F 4 FIG. I

LuCoP0 m v [n m] INVENTOR:

FRANZ HUND.

BY L Horn BURGESS, DINKLAGE & SPRUNG PAIENTEDAUGZI Ian 3753.754

SHEEI 2 OF 4 Q FIG.

LuZnVO5 CeFeBO CaCr Si 0 F V nm] INVENTOR: Franz Hund By: L. Horn BURGESS, DINKLAGE & SPRUNG PATENIEUAUSZI ms 375375 saw 3 BF 4 FIG. 3 [k cCuVO F LOO 500 600 700 V [nm] INVENTOR: Franz Hund By: L. Horn BURGESS, DINKLAGE & SPRUNG PAIENTEDMIBZI ma 3753754 SHEET h 0F 4 A FIG. 4 r A ThFeBOg INVENTOR: Franz Hund By: L. Horn BURGESS, DINKLAGE & SPRUNG MIXED PHASES F SPHENE STRUCTURE This invention relates to mixed phases in which compounds of sphene structure occur as the host lattice.

The mineral sphene or titanite corresponding to the formula CaTiSiO the mineral tin sphene or malayite corresponding to the formula CaSnSiO and the synthetic compound known as barium sphene, BaTiSiO have the same general formula and belong to the island silicates with isolated SiO,,-units in the lattice. The compound CaTiSiC) which crystallizes in the spatial group C with four molecules per monoclinic cell, and the mineral titanite or sphene have the lattice constants, a 6.567 1 0.005; b 8.723 0.005; c 7.454 r 0.005 A. and the monoclinic angle [3 ll952' i 2'. From X-ray examinations conducted on the mineral sphene [W. H. Zachariasen, Z. Krist 73, 7 (1930) the relative diffraction intensities J/J, and the intervals d in A. of the various lattice planes h k I are compared with one another in the following Table:

No. h k 1 III; d/A. No. b k 1 1 11 d/A.

T 1 1 30 4.93 12... 1 a 1.945 1 1 1(002) 100 3.233 13... 2 0 4(510) 5 1.848 2 o 2 90 2.989 14... 0 4 2(241) 10 1.802 4.--.. 2 0 0 5 2.841 15... s s 2 1.741 2 2 1(022 90 2.595 16... 2 4 0 10 1.725 5----. I 1 3 220) 5 2.352 17.-. 2 2 4 1.703 1 1 2632) 30 2.273 18... 5 3 3 401545 8..... 1 3 1 5 2.225 19... 1 5 1(241) 20 1.554 3 1 2 20 2.101 20..- 0 4 3634) 10 1.527 10---. 5 1 1 40 2.058 21... 1 a 3 40 1.494 11--.. 2 2 1 10 1.972 22... 4 0 0 40 1.418

The isotype compounds CaTiSiO, and CaSnSiO together form an ideal series of homogenous solid solutions (isotype mixed phases) over the entire range of mixtures of from 0 to I00 mole percent of each.

In order to express the sphene structure in simple terms, the general formula MMeZX, or MMeZX,Y is used in the context of this invention to represent both the pure mixed hosts (isotype mixed phases) and the variety of different sphene mixed phases (heterotype mixed phases); in the hosts, M Ca, Ba; Me Ti, Sn; Z=Si,X=O" and Y=O,OH F.

The production of heterotype mixed phases of the Si- O or rutile structure as host lattice has already been describedtfor example Z. anorg. allg. Chemie 321, l (1963) and Angew. Chemie 74, 23 (1962)). Under certain conditions, considerably more than half of all the elements of the Periodic System can be incorporated into the aforementioned host lattice as guest components in solid solution in cases where the ratio of the sum total of the newly enteringcations to the sum total of the newly entering anions is substantially 2 and in cases where the average statistical cationic radius is within the limits, determined by the particular type of structure.

Heterotype mixed-phase formation in a variety of different host lattices represents a commercially interesting field of inorganic chemistry. This oxide and fluoride chemistry with its manifold continuously variable possibilities of modification and its widely expanded fields of solid solutions only has a counterpart in the related field of the chemistry of metals and alloys. From the synthetic point of view, there are considerable possibilities for variation and by selecting suitable host and guest components it is possible systematically to prepare systems with special properties.

It is accordingly an object of the invention to provide a mixed phase of sphene structure containing guest components which impart thereto a spectrum of color values while retaining the original host lattice structure.

In accordance with the invention, synthetic phases of sphene structure corresponding to the general formula MMeZX or MMeXZ Y have now been found, being distinguished by the fact that they contain as host components pure or isotype mixed phases in which M =calcium and/or barium, Me titanium and/or tin, Z silicon, X oxygen and Y fluorine and/or the hydroxyl group, and further by the fact that at least 0.1 percent by weight of one or more of the following guest components can occur in place of the aforementioned host components without affecting the sphene structure or electro-neutrality in any way: for Z dipentavalent cations with ionic radii of less than substantially 0.6 A. and zinc cations, for Me mono to hexavalent cations with radii of from substantially 0.45 to 1.0 A. and for M monoto tetravalent cations with radii of greater than substantially 0.9 A., the stoichiometric ratios for (Me M):Z:(X Y) being substantially 2:15.

In this connection, the oxides, fluorides'or hydroxides which, basically, are not usually consistent in their structure with that of the host, can be incorporated in accordance with the incorporation equations set out in Table 1. Table 2 lists other formulae which show how for example the divalent and trivalent M-cations set out in Table l, the divalent, trivalent and tetravalent Mecations and the tetravalent Z-cations can be statistically replaced by differently charged cations.

Any of the elements mentioned in Table 3 represent suitable incorporatable elements.

TABLE 1.INCORPORATION EQUATIONS FOR SPHENE MIXED PHASESI TABLE z s'ra'rts'rlcar. REPLACEMTIT 5555-5115255 IN SPHENE MIXED PHASES TABLE 2.-STAT1ST1CAL REPLACEMENT OE ELEMENTS 1N SPIIENE MIXED PHASES -Cntmued TABLE 3.ELEMEN'IS WHICH oAN Br: ficoizi dmrnb IN SPHENE MIXED PHASES M1 Na, K, Rb, Cs, Fr Cu, Ag, Tl M11..." Ca, Sr, Ba, Ba, C Hg Eu, Pb, Mn M T1, La, El. 55-71, Ac, El. 91-103, Bi

Me Li, Cu, Na Me" Mg, Zn, Mn, Fe, Co, Ni, Cu, Sn, Pd, Pt Me A1 Sc, Tl, Rh, As, Sb, Bi, V, Nb, Cr, Mn,

e In, 00 Me".-. Tl, sin, Ge, Zr, Hf, Mn, Cr, M0,W, Nb, Os, Pt, Pb, Pu, Ru,

Tb, 'Ie, w, Jr Me.... As, Sb, Bi, V Nb, Ta, Cr, Mn, Pa, At

Cd(ll) 1.03" HG(ll) 1.12" Eu(ll) 1.24" Pb(ll) =l.32

Mn(ll) 0.91 Te(lll) 1.05" La(lll) 1.22" El58(lll) Co(11) 0.82" Ni(lI) 0.78 Cu(11) 0.72 Sn(ll) 0.93 Pd(ll) 0.80 Pt(ll) 0.80" A1(111) 0.57

0.92 Co(lll) On the basis of the incorporation equations set out in Table 1, the tetravalent elements Si, Ge, V can be incorporated in the Z-position in CaTiSiO BaTiSiO CaSnSiO, or in the isotype mixed phases of CaTi, ,,Sn ,SiO, in which x 0.01 to 0.99 as hosts of the general formula MMeZX or MMeZX Y, in accordance with equations (1) to (7), the pentavalent elements P, As, V, Cr, Mn in accordance with equations (8) to 15), the divalent elements Be, Zn in accordance with equations (16) to (20) and the trivalent elements B, Al in accordance with equations (19) to (21), in which case, in the mixed phase pigments formed corresponding to the general formula MMeZX MMeZX Y, M+Me is generally 2 while electroneutrality is guaranteed. The following general rules can be derived from the individual examples given hereinafter in regard to the ionic radii according to Goldschmidt: with the exception of Zn(11) which has an ionic radius of 0.83 A. but which is known to move very readily into the tetrahedron position, 2- to 5-valent elements with radii of less than about 0.60 A. are found in the Z- position, 1- to 6-valent elements with radii of from about 0.45 A. to about 0.98 A. in the Me-position and lto 4-valent elements with radii of greater than 0.90 A. in the M-position. The elements which can be incorporated altogether are set out in Table 3.

The methods used to investigate and display the new sphene mixed phase pigments are the same as those described in Angew. Chemie 74, 23 (1963) for mixed phase pigments of the rutile structure, in Z. anorg. allg. Chem. 321, l (1963) for heterotype mixed phases with SiO -structures and in Ber.dtsch.Keram. Ges. 42, 251 (1965) for heterotype mixed phases of the fluorite or fluorite-like structure.

Sphene mixed phase formation in accordance with the equations set out in Table l with CaTiSiO or BaTiSiO or CaSnSiO or the isotype solid solutions of CaTi, ,,Sn,,SiO with x 0.01 to 0.99 as hosts was assumedto have taken place when, according to X-ray investigation, at least percent by weight of more of guest components had been incorporated in solid solution into the hosts. Guest components can be incorporated into the host lattice for as long as the sphene structure remains intact. The upper limit of solubility with increasing quantity of guest component has not been determined, although in many cases it would appear to amount to about 50 percent by weight or more, the upper limit being that at which the structure changes significantly. Despite exhaustion of the many possible mixed-phase formations, their chemical composition can be varied to an extent such as has never been known in the chemistry of alloys. All the elements of the Periodic System with the exception of C, N, S, Se, Cl, Br and l and the noble gases can be incorporated through mixed-phase formation into a sphene host lattice on the basis of the 21 incorporation equations.

Literature references have already been quoted in regard to the production of mixed-phase pigments by the methods adopted in the chemistry of solids. The mixed phases can be produced in different ways. First of all, it is possible to heat the separately prepared host substances and the guest substances (each in the required quantity) together in finely powdered form. It is also possible initially to prepare only the host substance or only the guest substance and then to mix it together with the individual components of the particular guest or host substance (again in the required ratio), followed by heating. However, it is preferred simply to mix the individual starting components, both for the host and for the guest component, intimately together, followed by heating. The advantage of this procedure is that effective statistical distribution of the individual components is actually achieved before calcination, thus creating short diffusion paths.

The intensively ground components are heated either in air, 0 N,, H,O or in noble-gas atmosphere under reduced, normal or excess pressure, to temperatures of from about 200 to l,500 C and preferably to temperatures of from about l,l00 to 1,400 C. To reduce the reaction temperature, it can be of advantage to add fluxes and fusing agents, so-called mineralizers, to the reaction mixture before or during calcination. Suitable fluxes include alkali-metal and alkaline-earth metal halides, hydroxides, or carbonates, although boron, lead or bismuth oxides and halogen compounds can also be used. Alkali-metal fluorides such as sodium fluoride or potassium fluoride, for example, are particularly suitable.

Although the components can be heated in dry form it is also possible to prepare the reaction mixture by complete or partial reaction in aqueous or liquid organic media. Suitable starting materials include both natural and also syntheticically prepared reactants, in which connection it is not necessary to use only the oxides, fluorides or hydroxides. It is also possible to use thermally unstable compounds of the elements on which the components are based ov their solutions which, when heated, are converted into the components of the mixed-phase pigments. For example, it is also possible to use carbonates, nitrates, oxalates, formates or acetates in the corresponding stoichiometric quantities.

The heating time can be varied within a relatively wide range although periods of from about 5 minutes to 24 hours are usually sufficient. Heating can be carried out either in a single stage or in several stages under different temperature, time and pressure conditions. In this connection, it is possible to work both in an oxidizing atmosphere, i.e., in the presence of oxidizing gases such as oxygen or oxygen-containing gases for example, or in the presence of reducing gases such as hydrogen or carbon monoxide, for example, or in an inert gas atmosphere such as nitrogen or argon for example.

The guest components may be added either all at once or in several stages. The quantity in which the guest components are added in governed both by the host and by the components to be absorbed and also by the required properties of the end product. It has already been mentioned that distinct mixed phase are most readily identified where the guest components are added in quantities of from about 10 percent to less than about 50 percent. However, the guest components can also be present in considerably smaller quantities such as 0.1 percent, for'example, and still be technically interesting.

The Examples are set out in Table 4 to 24. The number of the incorporation equation (in some cases subgroup where an element is statistically replaced in accordance with Table 2) is followed by the test number, the theoretical formula of the guest substance, the quantity in which it is present (g) for 5 g of the host, the maximum calcining temperature at which the host lattice alone was still visible in the X-ray photographs, coming from low temperatures after repeated calcination for 30 minutes and renewed intensive pulverizing of the mixture. The visually observed color of each of the sphene mixed-phase pigments is shown in the last column.

The spectral remission curves for a few selected examples of these novel sphene mixed-phase pigments are shown in FIGS. 1 to 4, the wave length 0, being plotted on the abscissa and the remission R on the ordinate. With CaTiSiO, as host, a light gray yellow pigment is found with PbNiPO F in FIG. 1 for example, and a green pigment with tinges of gray or a gray pigment with tinges of blue with LaCoPO or BaCoPO F, while in FIG. 2 a beige gray pigment is found with LaZnVO a beige brown pigment with CeFeBO and a gray brown pigmentwith CaCrSiO F. With CaSnSiO, as host, FIG. 3 shows the spectral remission curve with KVSiO,,,for a light green pigment, with LaColPO for a gray violet pigment and with CaCuVO for an olive-colored pigment, while FIG.]4 shows the spectral remission curve with ThFeBO for a beige-colored pigment, with LaCrSiO for a pink brown pigment tinged with blue and with CaCr V,, SiO for a dark brown pigment tinged with violet. In other words it is possible to obtain a variety of required shades with the aid of these mixed phases.

The novel calcium-titanium, barium-titanium, and calcium-tin sphene mixed-phase pigments are valuable high-temperature-resistant inorganic pigments for coloring enamel and ceramic glazes, considerably widen-. ing the existing range of colors.

Ceramic products (plates) can be colored with the aforementioned synthetic mixed phases of sphene structure by clouded zircon frits. For this purpose is used for example a zircon enamel containing 56% SiO 10.3% A1 0 10.9% B 0 6.7% CaO, 0.1% MgO, 3.6% ZnO, 4.6% Na O, 1.2% K 0, 6.5% ZrO 0.1% Fe O g of this enamel are mixed in a ball mill at high speed with 2 g of the synthetic mixed phases of sphene structure, e.g., number 46 CaTiSiO /LaFeSiO number 238 CaSnSiO /LaTrSiO, or number 247 CaSnSiOJTbMgSiO and 42 ml water.

The slip obtained is applied to ceramic plates at a 5 white-yellow color are thus obtained.

8 layer thickness of a bout 0.8 1 mm and welldri e d. The coated plates are heated in an electric furnace up to about 1,000C and kept at that temperature for half an hour. Colored enamels of gray-beige, pink-brown and Sphene mixed phases with CaTiSiOs as host (Incorporation equations 1; 5a-5e; 1/6a) Incorporation Test Compound Quantity Max. temp.

equation No incorporated in g. l 0.] Color of the mixed phase 1 CaMnSiO 1. 295 1, 250 Fawn-olive.

1 CaZ rSiO; 2. 618 1,350 Beige-white.

1 IbTiSlO 0.260 1,150/411 lale yellow.

1 MnIiSiOs 2. 000 1, 250 Pale olive-gray.

1 CaV SiO5 1. 000 1,150 Gray-brown.

1 CaTi GeO5 5.000 1.350 Yellow-white.

1 CaTiV O 1. 000 1, 250/N; Pale gray-brown.

1 PbTiV O 1. 000 l, 150/N; Beige-brwn-gray. 1... CaSnV O 1. 000 1,350/3h/N2 Gray.

1/5a. CBAh/zSbr/zSlOs 1. 000 250/3 White-gray.

1/59... CaRhuzSbmSiOs 2.000 1, 250/3h Yellow-brown.

U (Each/2 1125105 2.000 1, 350 Brown, tinges of olive. 1/5a. CaSb1 zSb1/2Si05 2.000 1, 350/Nz White-gray.

1/5a CB-Mlh/gSbl/ZSlO!) 2.000 1, 250/3h/O; Light-gray olive. 1/5a CaFei zSb1 zSi05 2.000 1, 250/3h Pale yellow.

1/59... CaF81/2Sb1 2SiO5 2.000 1, 250/3h Do.

1/5a. CaCOmS bmSiO 2.000 1, 250/311/0 Olive-yellow.

1/5a.. CaAh/zV 1115105 2.000 1, 250/3h Yellow-beige.

1/5a. CaRhmVuzSiQ 2.000 1, 250/3h Reddish gray-brown. 1/5a.. CaCrmV zSiO5 2.000 1,350 Dark gray-brown. 1/5a CaSb1/z 1 zSi05 2. 000 1,250/3h/N Gray-brown.

1/5a. CaM n1/zV zSi05 2.000 1,100/02 Dirty brown.

1/5a- CaFe1 zV1 zSiO5 2. 000 1,250 Yellow-olive.

1/58... CaComVmSi05 2.000 1, l00/4h/O2 Green-olive, gray tinges. 1/5a.. CaFe1/2NbmSiO5 1. 000 1,250 Yellow-gray.

1/5a. CaCr /zTa zSiO5 1. 000 1, 250 Dark brown.

1/5b. CaNim NbmSiOr 1. 000 1, 250 Greenish-gray.

1/5b CaComTam-siO 1. 000 1,250 Green, gray tinges. 1/5b. CaZnmVmSiO5 1. 000 1, 250 Brown-gray.

1/5e CaLi1 4V3/4SiO5 1.000 1,250 Do.

1/5d.. CH-Cl'z/aWmSlOs 0.5000 1,250 Fawn red brown. 1/5d CaFemW1/3SiO5 0.5000 1, 250 Fawn yellow.

l/5e CaNi 1/zVV 1 zSlO5 0. 500 1, 250 Gray-yellow.

1/5e CaCm W 810 0. 500 1, 250 Pale gray.

1/6a Ml'lTiB1/zP /zO 1. 000 1,250 Gray brown.

Sphene mixed phases with CaTiSiO as host (Incorporation equations 2; 3; 3/2a) Incorporation Test Compound Quantity Max. temp. equation No. incorporated in g. P Color of the mixed phase 36 KSbSiOz, 1. 000 1, 250/3h Gray, olive tinges. 37 NBVSlOs 1. 000 1,150 Dirty beige. 38 NaTaSiOr. 1. 000 1, 250/3h Pale gray. 39 N aSbSlO5 1.000 1, 250/3h Pale green gray. 40 AgVSiOs 1.000 1,150 Beige brown. 41 AgNbSiO 1.000 1, 250/311 Gray beige. 42 AgSbSiO 1. 000 1, 250/3h Gray violet. 43 LaAlSiOs 1. 000 1, 250/3 whitish yellow. 44 LaMnSiO5 1.000 1, 250/Or Olive gray. 45 LaCrSiOs 1. 000 1,250 Yellowish brown. 46 LaFeSiO5 1. 000 1,250 Gray-beige. 47 LaCaSiO 1. 000 1, 250 Green gray. 48 NdA1SiO5 1. 000 1, 250 Gray white. 49 PrAlSiOr 1.000 1,250 Gray, yellow tinges. 50 TbAlSiO5 1.000 1,250 Yellow gray. 51 Cai/acemCr siOr 1.000 1, 250 Black-brown.

Sphene mixed phases with C-aTiSiOs as host (Inrorporaiion equations 4; 5)

Incorporation Test Compound Quantity Max. temp. equation No incorporated in g. 0.] Color of the mixed phase 52 IrMgSiO 1. 000 1, 250/4h/O2 Greenish yellow. 53 TbMgSiO5 1. 000 1, 250/02 Gray yellow. 54 CeMgSiOs 1. 000 r 1,250 Beige yellow. 55 PrZnSiOs 1. 000 1, 250/02 Pale yellow. 56 TbZnSiOs 1. 000 1, 250/02 Beige yellow. 57 CeZnSiOs 1.000 1,250 Do. 58 CeC0SiO5 1. 000 1, 250 Dark gray. 59 CeCuSiO 1. 000 1,250 Beige. 60 C6N1Si05 1. 000 1, 250 Yellow brown. 61 CeFeSiOr, 1. 000 1, 250/N2 Gray beige.- 62 CeMnSiO5 l. 000 1, 250/N2 Brown gray. 63 ThZnSiO 1. 000 1, 250/611 Pale yellow. 64 ThCOSlOs 1. 000 1, 250 Gray-violet. 65 ThCuSi05 1. 000 1, 250 Brown beige. 66 ThNiSiOs 1. 000 1, 250 Do. 67 ThFeSiOs 1. 000 1, 250/Nz Yellow brown. 68 ThMnSiOs 1. 000 1, 250/Nz Yellow, green tinges. 69 KTlSlO-iF 1. 000 1,150 White. 70 KSnSlOrF 1. 000 1,150 Do. 71 NuIiSiOrF 1. 000 1, 250 Yellow white. 72 NaSnSiOrF 1. 000 1,250 Do. 73 NnllSimF 1. 000 1,250/311 White.

Sphene mixed phases with CaTiSlO; as host ([neorporation equations 6; 7; 8)

Incorporation Test Compound Quantity Max. temp. equation No incorporated in g. P 0.] Color oi the mixed phase 74 CaAlSiOrF l. 000 1, 250 Yellow white. 75 CaFeSiO4F 1. 000 1, 250 Beige, brown tinges. 76 CaCrSiOiF 0. 500 1, 250 Gray brown. 77 CaMnSiOaF 1. 000 1,250 Brown, gray tinges. 78 SrCrSiO4F 1.000 1,250 Yellow brown. 79 BaFeSlO4F 1. 000 1, 250 Olive yellow. 80 BaMnsiOiF 1. 000 1, 250 Gray brown. 81 PbA1SlO4F 1.000 1,250 Pale yellow. 82 PbCrSiOiF 1. 000 1, 250 Brown, gray tinges. 83 SrCrSiO4(OH) 1. 000 1, 250/3h Blaekish brown. 84 LaMgSlO|F 1. 000 1, 250/311 Whitish gray. B5 LaNiSi0 F 1. 000 1, 250/611 Yellow, olive tlnges. 86 LaZnVOs 1. 000 1, 250/3h Brownish-gray. 87 LaMnVO 1. 000 1, 150/311 Dark brown. 88 LaFeVO, 1. 000 1, 150/311 Brown yellow. 89 LaZnPO 1. 000 1, 250/311 Blue gray. 90 LaMnPOi 0.5000 1, 250/3h Beige brown. 91 LaFePO 1. 000 1, 150/3h Brown. 92 LaCoPO; 1. 000 1, 250/3h Green, gray tinges. 93 LaNiPO 1. 000 1, 250/3h Yellow-gray. 94 LaCuPO 1. 000 1, 150 Gray-green.

Sphene mixed phases with CaTiSiOms host (incorporation equations 9', 10; 11)

Incorporation Test Compound Quantity Max. temp. equation N o. incorporated in g. l" (3.] Color of the mixed phase 95 CaAlPOi 1.000 1, 250/611 White yellow. 96 CaCrPOi 1. 000 1,350 Gray brown. 97 CaSbPO 2.000 1,150/4h/N3 White, gray tinges. 98 CaMnPO; 1. 000 1,250/611/0 Dirty yellow. 99 CaFePO; 1. 000 1, 250/3h Gray yellow. 100 CaCoPO; 1. 000 1, 250/3h Green gray. 101 NaSnPO 1. 000 1, 350 White beige. 102 KCePO 0. 500 1, 250/311 Green gray. 103 KTiPO 1. 000 1, 250/3h Whitish gray. 104 KSnPO, 1. 000 1, 250/311 Whitish. yellow. 105 KCeVO 1. 000 1, 250/311 Gray brown. 106 KIiVO 1.000 1,150 Pale gray brown. 107 KBnVOi 1. 000 1, 250/311 Do. 108 KSHCIVO5 1. 000 1,250/0 Pink violet. 109 'IhLiVO 1.000 1, 250/011 Gray brown. 110 CeLiPO 1.000 1, 250/6h Yellow olive.

Sphene mixed phases with CaTiSlOi as host (Incorporation equations 12; 13)

Ineor oration Test Compound Quantity Max. temp. equat i on No. incorporated in g. 0.] Color 01 the mixed phase 12... 111 KAlPOiF 0.500 1,250 Dirty white. 12 112 KCrP04F 1.000 1,150 Dirty brown. 12 113 NaAlPOiF 0. 500 1, 250 Yellow white. 12 114 NaFePO4F 1. 000 1,150 Gray brown. 12 115 NaMnPO|F 1. 000 1,150 Brown, gray tinges. 12 116 KAiVOiF 1. 000 1, 150 Pale beige brown. 12 117 NaFeVO F 1. 000 1,150 Beige brown. 12.. 118 NaCrVO4F 1. 000 1, 150 Dark brown. 12 119 NaMnVO4F 1. 000 1,150 Do. 12,. 120 N8MHVO4(OH) 1. 000 1,150/01 Gray brown. 13.. 121 LaLiVO4F 1. 000 1,150 Do. 13 BiL1PO F 1.000 1,250 Light gray yellow.

Sphene mixed phases with Ca'IiSiOs as host I (Incorporation equations 14; 15)

Incorporation Test Compound Quantity Max. temp. equation No incorporated in g. C.] Color of the mixed phase 123 CaCoPOlF 1. 000 1,150 Dark green. 124 CaNiPorF 1. 000 1, 250 Pale yellow. 125 CaCuPorF 1. 000 1, 250 Gray green olive. 126 CaZnPOrF 1. 000 1,250 White yellow. 127 SrC0PO4F 1. 000 1, 150/3h Gray green, blue tinges. 128 SrCuPO4F 0. 500 1, 25 Yellowish gray-olive. 129 SrMgPO F 1. 000 1, 250/311 White yellow. 130 BaCoPOrF 1. 000 1, 150 Gray, blue tinges. 131 BaNiPOrF 0. 500 1, 250 Olive yellow. 132 BaCuPo F 1. 000 1, 150 Yellow gray green. 133 BaZnPO4F 0.500 1, 250 White yellow. 134 PbNiPO4F 1. 000 1, 150 Pale gray yellow. 135 PbZnPOlF '1. 000 1, 150/311 Pale yellow. 186 CaC0VO1F 1. 000 1, 150 Olive gray. 137 CaNiVO4F 0.500 1, 250 Gray beige. 138 CaCuVO1F 1. 000 1, 150 Dark gray. 139 CaZnVO F 1. 000 1, 150 Gray beige brown. 140 SrNiVO4F l. 000 1, 150 Beige yellow, olive tinges. 141 SrZnVOrF 0.500 1, 250 Beige, gray tinges. 142 BaNIVO4F 1. 000 1, 150 Yellow olive gray tinges. 143 BaMgVO4F 0.500 1, 250 Beige, gray tinges. 144 PbCilVOrF 1. 000 1, 150 Gray olive. 145 PbZnVO4F 0.500 1, 250 Light beige. 146 CaCoPO1(OH) 1. 000 1, 250/3h Gray green.

Sphene mixed phases with CaTiSiO as host (Incorporation equations 16; 17; 18; 19)

Incorporation Test Compound Quantity Max. temp. equation N o incorporated in g. P 0.] Color of the mixed phase 147 CeTiBeOt 1. 000 1, 250/311 Gray green. 148 CeSnBeOt 1. 000 1, 250/311 Gray yellow brown. 149 LaNbBeOs 1. 000 1, 250/311 Light gray. 150 LBVBBO5 1. 000 1, 250/311 Light gray brown. 151 PbWBeOs 0. 500 1, 250/211 Beige yellow. 152 CaVBOr 1. 000 1, 150 Light brown gray. 153 CaNbBOa 1. 000 1, 250/3h Light gray. 154 CaTaBOr 1. 000 1, 250/3h Do. 156 CaSbBOr l. 000 1, 250/3h Greenish gray. 157 BaVBOt 1. 000 1, 150 Gray brown. 158 BaNbBOs 0. 500 1, 250/311 Light gray. 159 BaTaBO5 1. 000 1, 250/3h Do. 160 BaSbBOt 1. 000 1, 250/3h Green gray.

Sphene mixed phases with CaTiSiOs as host (Incorporation equations 20; 20/2a) Incorporation Test Compound Quantity Max. temp. equation N o incorporated in g. P C.] Color of the mixed phase 161 PrTiBO: 1. 000 1, 150 Light gray yellow. 162 TbTiBO5 1. 000 1, 250 Gray beige. 163 NdTiBO 1. 000 1, 250 Brown gray. 164 Ce'IiBO5 1. 000 1, 150/N2 Gray beige brown. 165 PrSnBO 1. 000 1, 150 Yellow, gray tinges. 166 TbSnBO 1.000 1,250 Whitish beige. 167 NdSnBO5 1. 000 1, 250 White gray. 168 CeSnBOs 1. 000 1,150/Nz Beige gray. 169 LaCr Bo 1.000 1, 250/Oz Reddish brown. 170 EuSnBOs 1. 000 1, 350 Light blue gray. 171 PrSnAlOs 1. 000 1, 250 Green yellow. 172 LaCr AlO5 0.500 1,250 Brown gray. 173 LaSnAlOr 1. 000 1,250 Gray yellow. 174 PrmCayzTiBOs 1. 000 1, 250/O1 Pale yellow. 175 Tb zCamTiBO 1. 000 1, 250/Oz Beige yellow. 176 CemCamTBO 1.000 1, 250/6h Light yellow beige. 177 PmzCayzSnBO 1. 000 1, 2150/0; Light gray. 178 TbmCfimSllBOs 1.000 1,350/02 D0. 179 CemCamSnBQ', 1. 000 1,250 Gray yellow. 180 CemCEh/zSnAlO 1. 000 1, 250 Do.

Sphene mixed phases with CaTiSiOr as host (Incorporation equation 21) Incorporation Test Compound Quantity Max. temp. equation No. incorporated in g. P 0.] Color of the mixed phase 181 PrAlB O5 1. 000 1, 250/O2 Light yellow. 182 'IbAlBO 1. 000 1, 250/O2 Beige yellow. 183 CeAlB O5 1. 000 1, 250 Beige gray. 184 CeCrBOs 1. 000 1, 250/3h Dark olive. 185 CeMnBO5 1. 000 1, 250/3h Brown, red tingcs. 186 CeFeBOr 1. 000 1, 150/311 Beige brown. 187 'IhCrB O5 1. 000 1, 250/3h Dark brown. 188 ThMnB O 0. 500 1, 250/3h Brown heige. 189 ThFeBOs 1. 000 1, 250/311 Gray, olive tinges.

Sphene mixed phases with CaTiSi0 as host Incorporation Test Compound Quantity Max. temp. equation No incorporated in g. P C.] Color of the mixed phase 190 BaCri v sios 1. 000 1, 150 Yellow olive. 191 Bach/251211125105 1.000 1,150 Olive. 192 VSiO 1. 000 1,150 Beige yellow. 193 LaCrSiO 1. 000 1,150 live. 194 BaCrSiOaF 1.000 1,150 Do. 195 LaCoPO 1.000 1,150 Violet blue. 106 LaZnVO 1. 000 1,000 Light gray yellow. 197 KCrVO4F 1.000 1, 150 Gray-olive. 198 KCrVOAOH) 1.000 1,150 Olive. 109 BaC0VO4F 1.000 1,150 Do. 200 BaCuVO4F 1. 000 1, 150 Gray beige brown. 201 BaCoPO4F 1.000 1,150 Gray. 202 BaCoVOKOH) 0.500 1, 000 Dark brown. 203 PbNiPOqF 1.000 1,150 Green yellow. 204 PrSnBOs 1. 000 1, 150 Yellow, green tinges. 205 ThMn 'BO 0.500 1, 150 Beige brown. 206 ThFeBO 0.500 1,150 Gray yellow; olive tinges. 207 ThCrBOr 0.500 1 150/4h Gray-olive. 208 CeAlBOs L000 1,000 White gray. 200 CeFeBOr 1.000 1, 150 Brown beige.

Sphene mixed phases with CaSnSiOi as host (Incorporation equations 1; 1/59.)

Incorporation Test Compound Quantity Max.- temp. equation No. incorporated in g. 6.] Color of the mixedphase 210 CaCr Si05 2. 000 1,350 Brown, violet tinges. 211 CaFe SiO 2. 000 1, 250/3h/02 Gray brown. 212 PbSnSiO 1.250 1,350 White yellow. 213 CaCr SiQs 0.100 1,350/0; Violet, gray tinges. 214 CaMn S1O 1. 631 1, 250/3h Dark brown. 215 CaAlr/2Sb1 zSi0i 2. 000 ,250 Gray white. 216 CoRhmShmSiOt 1000 1 250/611 Beige brown. 217 CaMmnSlmzSiO 1. 000 1, 250/311 Gray, brown tinges. 21H (lilFlU HiH/ZSIU 2.000 1,250 Dirty yellow. 210 (hiAlmVmSim 2. 000 1,250 White yellow. 220 (Jultin zVmHlm 2. 000 1,250/311 lirown gray, pink tinges. 221 (JuCrmVuzSiO 2. 000 1,350 Urnnnish gray. 222 ()[iSln zVz/2Si05 2. 000 1,150/411 Light blue gray. 223 CaMru V1 1181 0 2.000 1 110/4h Gray yellow. 224 CuFei zv 1 128101 2. 000 1, 350 Orange yellow, olive tinges. 225 CaComvi/zsior. 2. 000 1,100/4h Gray, blue tinges.

Sphene mixed phases with CaSnSiOt host (Incorporation equations 2; 3)

Incor oration Test Compound Quantity Max. temp. equat on No incorporated in g. 0.] Color of the mixedphase 226 KVSiQs 1. 000 1,250/3h Light green. 227 KNbSiOs 1. 000 1, 250 Light gray. 228 K'IaSiOr 1. 000 1,250 White gray. 229 NaVSiOr 1. 000 1, 250 Yellow, green tinges. 230 NaNbSiOr 1. 000 1, 250 whitish gray. 231 N BTBS106 1. 000 1, 250/6h White. 232 NaSbBiO; 1. 000 1, 250/3h Light gray. 233 AgVSiO 1. 000 1, 250/3h Green gray. 234 AgNbSiOr 1. 000 1,250/311 Whitish gray. 235 AgSbSiO 1.000 1, 250/3h whitish yellow gray. 230 LuAiSiOr Z 0. 500 1, 0/211 Gray white. 237 LuMnSiOr 0.500 1, 350 (1 my brown. 238 LnflrSiO 1. 000 1,350 Pink brown, gray 11115508.- 230 111110 1110 1. 000 1, 350 1101111: gray. 240 1111 0 0111); 0. I100 1,350/211 1111101811 gray. Ml N11 A 11-00 1.000 1,050 White, violet times.

'2 irAiHiUr, 0.500 1,2160/211 Whltlnh arm-.11 yellow. .148 (HI/H3105 0. 500 1,850 whitish yellow. 244 LnUrSiO 2.000 1,350 Gray brown. 245 LnCrSiOt 2.000 1,350 Do.

Sphene mixed phases with CaSnSiOs as host (Incorporation equations 5; 5)

Incorporation Test Compound Quantity Max. temp. equation No incorporated in g. 0.] Color of the mixed phase 4 240 PrMgSiOi 0.500 1, 350/ 0 Gray yellow. 4 247 TbMgSlOs 1. 000 1, 350/02 ,Whitish yellow. 4 248 COMgSiOs 1. 000 1, 350 Blucish pray. I 240 lrZuSiOi 0. 500 1, 350/0; Gray yellow. 4 250 'rhznsioi 1. 000 1, 350/0: Do. 4 251 (02115105 1. 000 1, 350 Light gray. 4 252 CoCoSiOi 1. 000 1, 350 Blueish gray. 4 253 (39011510: 1. 000 1, 350 Beige brown gray. 4 254 C1N1S105 1. 000 1, 350 Gray, olive tinges.

Spheno mixed phases with CaSnSiOs as host-Continued 255 CeMnSiOs 1.000 1,350 Beige gray. 256 TllZllSiO5 1.000 1,350 Whitish gray yellow. 257 ThCoSiOs 1.000 1,350 Gray violet, blue tinges. 258 ThCuSiO5 1.000 1,350 Light gray green. 259 'IhNiSiO5 1.000 1, 350 Light gray beige. 260 ThFeSiO5 1. 000 1, 150/N2/8h Pale yellow. 261 'IhMnSiO5 1. 000 1, 350/N2 Whitish yellow. 262 KTiSiOrF 1. 000 1, 250 White. 263 KSnSiOrF 0. 500 1, 250 White yellow. 264 NaTiSiO4F 0. 500 1, 250 Yellow White. 265 KTiSiO4(OH) 1. 000 1, 250/3h White Pink.

Sphene mixed phases with CaSnSiOt as host (Incorporation equations 6; 7)

Incorporation Test Compound Quantity Max. temp. equation No incorporated in g. 0.] Color of the mixed phase 266 CaAlSiOrF 1.000 1, 250 White. 267 CaFeSiOiF 1.000 1,150 Brown yellow, olive tinges. 268 CaCrSiO4F 0.500 1, 250 Brown pink rod. 260 CaMnSiO4F 1.000 1, 250 Beige, olive tinges. 270 BaFeSiO4F 1. 000 1, 250 Beige yellow. 271 BoMnSiO4F 1. 000 1,250 Gray brown. 272 PbAlSlOF 0. 500 1, 250 White yellow. 273 PbSrSi04F 1. 000 1, 250 llrownish violet. 274 CaCrSiO4(O1-l) 1. 000 1, 250/3h Pink colored. 275 LnMgSiOrF 0.500 1, 250/3li Dirty white. 276 BiMgSiO4F 1.000 1, 250/3h White yellow. 277 LBNlsiO4F 0.500 1, 250/311 Brown beige yellow.

Sphene mixed phases with CaSnSiO; as host (Incorporation equations 8; 9)

Incorporation Test Compound Quantity Max. temp. equation No ii'ieorporaterl in g. 0.] Color of the mixed phase 278 LaZnVOt 1.000 1, 250/3h Whitish green. 270 LaMnVO; 1.000 1, 250 Beige brown. 280 LaFeVO- 1.000 1, 250 Brown beige. 281 LaZnPO 0.500 1, 250 282 LaMnPOt 0.500 1, 250 Reddish brown. 283 LaFEPO; 0.500 1, 250 Beige yellow. 284 LaCePO5 0.500 1, 250 Gray-violet. 285 LaNlPO; 0.500 1, 250 Gray beige. 286 LaCuPO; 1.000 1, 250/6h Light gray green. 287 CaRhPO 2.000 1, 350 Dark brown. 289 CaCrPOs 2.000 1, 250/3h Violet. 290 CaCrVO 2.000 1, 350 Blackish brown. 291 CaFeVO; 2.000 1, 1.50/4h Orange yellow.

Sphene mixed phases with CaSnSiOs as host (Incorporation equations 10; 11; 12)

Incorporation Test Compound Quantity Max. temp. equation No incorporated in g. 0.] Color of the mixed phase 292 NAFe vQ- 2. 000 1,150/4h Green, olive tinges. 293 KCePOr 0. 500 1, 250/3h Light gray. 294 KTiPO 0.500 1, 250/6h White, pink tinges. 295 KSnPOs 0. 500 1, 250 Do. 296 KCaVO; 1. 000 1, 250/3h Light gray green. 297 KTiV0 1. 000 1, 250 Light yellow gray. 298 KSnVO 1. 000 1. 250/6h Light green. 299 KSnCrOr 1. 000 1, 250/3h/0z Pink violet. 300 NaV P05 0.500 1, 250 Whitish yellow. 301 ThLiVO; 0. 500 1, 250/311 Whitish gray yellow. 302 CeNaVO; 1.000 1, 250 Light greenish. 303 N aCrV04F 0.500 1, 250 Violet brown. 304 KFQVOrF 1. 000 1, 250/3h Beige bown. 305 KFeVOKOH) 1. 000 1, 250/3h Brown beige.

Sphene mixed phases with CaSnSiO; as host (Incorporation equations 13; 14/15; 16; 17)

Incorporation Test Compound Quantity Max. tem equation No. incorporated in g. CR] Color of the mixed phase 306 LaLiVOrF 1. 000 1, 250/3h Greenish, white gray. 307 BiLiPOiF 0.500 1, 250/3h Dirty white. 308 CaCoVOrF 1.000 1, 150 Gray, green tinges. 309 C8N1VO4F 0.500 1, 250 Greenish gray yellow. 310 CaCuVOrF 1.000 1, 150 Olive-gray. 311 CaZnVO4F 0.500 1,250 Fawn yellow green. 312 PbC11V04F 1.000 1,150 Olive, gray tinges. 313 PbZnVOiF 0.500 1, 250 Whitish yellow green. 314 CBCOVO4(O}I) 1.000 1,150 Dark gray green. 315 CeTiBeO; 1.000 1, 250/3h Light green gray. 316 CeSnBeO 0.500 1, 250/3h Gray, green tinges. 317 LaNbBeO 0.500 1, 250/311 White. 318 LaVBeO; 0.500 1, 250/3h Green, yellow tinges.

Sphene mixed phases witlrCaSnSiO; as host (Incorporation equations 18; 19: 20)

Incorporation Test Compound 1 Quantity Max. temp.

equation No incorporated in g. 0.] Color of the mixed phase 319 CaWBeO 0. 500 1, 250/3h White pink. 320 PbWBeOt 0. 500 .25 Do. -321 CaVBO; 0. 500 1, 250/3h Light yellow green. 322 CaNhBOs 1. 000 1, 250/6h Light gray. 323 CaTaBO 1. 000 1, 250/3h White gray. 324 CaSbBO 0. 500 1, 250 Light blue gray. 325 BaVBO 0.500 1,250 Whitish yellow green. 326 BaNbBO; 0. 500 1, 250 White gray. 327 BaTaBO 1. 000 1, 250 Whitish gray. 328 BaSbBO 1. 000 1, 250 Light blue gray. 320 Pri'IiBO 0. 500 1, 350 Light green yellow. 330 Tb'IiB0 1. 000 1,350 Beige yellow. 33] Nd'IiBO, 0. 500 1,350 White gray. 332 CcIiBO, 1. 000 I l50/8h/Nz Brown gray. 833 lrSnIiO 1.000 1,350 Whitish yellow. 334 'ibSnBth; 1.000 1,350 White yellow. 385 NdSnBO 1.000 1,350 Violet gray. 336 ()cSnBO, i. 000 1,150/8h/N; whitish green grey. 337 LeCr Bor 1. 000 1,350/01 Brown gray. 338 LnTiAlO 1. 000 1, 250/3h White. 339 NdSnAl 1. 000 250 Do. 340 1. 000 1, 250 Whitish gray.

CeTiAlOa Sphene mixed phases with Ca SnS nSiO5 as host V (Incorporation equations /2a; 21)

Incorporation Test Compound Quantity Max. temp. equation No. incorporated in g. P 0.] Color 0! the mixed phase 341 PrmCailzTiBoa 1.000 1,350 Gray, green tinges. 342 Tb1/2Cal/2TB05 0.500 1,350/2h White. 343 Ce1/2C8i/2TlBO5 0.500 1,350 whitish yellow brown. 344 PHIQCBi/ZSHBO 0.500 1,350 White, 345 TbuzCamSnBOs 0.500 1,350 Do. 346 CemCamSnBO 1.000 1,350 Greenishgray. 347 TaAlBO 0.500 1,350/2h Whitish yellow. 348 CeAlBO 0.500 1,350 Light gray. 340 CcCrBO; 1.000 1,250/3h Violet brown. 350 CeMnBO 1.000 1,250 Blackgray. 351 'IhCrBO; 1.000 1,250 Brownolive. 352 ThMnBO 1.000 1,250 Violetred. 353 'IhFeBOr 1.000 1,250 Gray brown 354 ThFeBOs 1.000 1,250 Brown olive tinges.

Sphene mixed phases with 75 moi percent of CaSnSiQs plus mol percent of CaTiSiCs ashost Incorporation Test Compound Quantity Max. temp.

equation No. incorporated in g. 0.] Color of the mixed hase 355 LaCrSi0 0.100 1, 250/3h Pink, gray tinges. 356 ThFeBOs 0.500 1,250 Gray yellow. 357 LBCOPO5 1.000 1,250 Blue-gray.

Sphene mixed phases with moi percent of CaSnSiOa plus 50 mol percent of CaTiSiOt as host Incorporation Test Compound Quantity Max. temp.

equation No. incorporated in g. 0.] Color of the mixed phase 358 LeCrSim 0.1000 1, 250/3h Pink 850 'lhFeiiO 0. 500 1, 250 Gray yellow. 300 LnColO 1.000 1,250

Blueish green grey.

Spin-no mixed phases with 25 mol percent of ()nSnSiOs plus mol percent of (IaTiSiOs as host incorporation 'inst Compound Quantity Max. tem p.

equation No. incorporated in 1:. (1.] Color of the mixed phase {till inti rhiilh (l. 1, 250/331 iirownish pink. 302 'iili oiiUr, 0. 500 1,250 (iruy yellow. 303 Laiioiih, 1.000 1, 250 Gray green.

What is claimed is:

1. Synthetic mixed phases of sphene structure corresponding to the general formula MMeZX or MMeZX Y and comprising as host components pure or isotype mixed phases in which M calcium and/or barium, Me titanium and/or tin, Z silicon, X oxygen and Y fluorine and/or hydroxyl, comprising at least about 0.1 percent by weight of at least one guest component in place of the aforementioned host components without any change in the sphene structure or in the electroneutrality, the guest component for Z being a di-valent to pentavalent cation with an ionic radius of less than about 0.6 A. and/or a zinc cation, for Me being a monoto hexavalent cation with a radius of from about 0.45 A. to about 1.0 A. and for M being a monoto tetra-valent cation with a radius of greater than about 0.9 A., the stoichiometric quantities for (Me+M):Z:(X+Y) being about 2:115.

2. Synthetic mixed phases of sphene structure according to claim 1, wherein Z is replaced at least in part by a guest component which is one or more of beryllium (ll), zinc (ll), boron (Ill), aluminum (Ill), silicon (IV), germanium (IV), vanadium (lV), phosphorus (V), arsenic (V), vanadium (V), chromium (V), and manganese(V).

3. Synthetic mixed phases of sphene structure according to claim 1 wherein the host component comprises CaTiSiO 4. Synthetic mixed phases of sphene structure according to claim '1 wherein the host component comprises CaSnSiO 5. Synthetic mixed phases of sphene structure according to claim 1, wherein the host component comprises an isotype mixed phase of CaTiSiO and CaSnSiO of the formula CaTi ,Sn,SiO,, in which x 0.01 to 99.9.

6. Synthetic mixed phases of sphene structure according to claim 1 wherein the guest component or components are present in an amount of about 0.1 to 50 percent by weight.

1 122x3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3.753.754 Dated August 21, 1973 Inventor(s) Franz Hund It is certified that error appears in the aboye-identified patent and that said Letters Patent are hereby corrected as shown below:

. C01. 1,. line 30, Table item 18, change "1.645" to 1.643

col. 2, line 10, chan e "MMeXZ Y" to MMeZX Y C01. 3, lines 13 and 15, Table 2, items 4e and 5f, change "V to VI C01. 3, line-39, Table 3, change O" to 0= C01. 3, 1ine "54, change "HG" to Hg C01. 5, line 59, change "ov"' to "or".

Col. 6, line 12., change "in" to is C01, 6, line 22, change"'1ab1e" to Tables Col. 9, in the Table test "57", under "Incorporation equation" change "4" to 4 Col. 13, in the title of the first table, change to BaTiSiO C01. 17, in the title of the second table, change "CaSnSnSiO to CaSnSiO C01. 17 Test 344, under "compound incorporated" change J n H Pr ca SnBo to Pr Ca SnB O Signed and sealed this 24th day of September 1974,

(SEAL) Attest:

McCOY M. GIBSON JR. C. MARSHALL DANN Commissioner of Patents 

2. Synthetic mixed phases of sphene structure according to claim 1, wherein Z is replaced at least in part by a guest component which is one or more of beryllium (II), zinc (II), boron (III), aluminum (III), silicon (IV), germanium (IV), vanadium (IV), phosphorus (V), arsenic (V), vanadium (V), chromium (V), and manganese(V).
 3. Synthetic mixed phases of sphene structure according to claim 1 wherein the host component comprises CaTiSiO5.
 4. Synthetic mixed phases of sphene structure according to claim 1 wherein the host component comprises CaSnSiO5.
 5. Synthetic mixed phases of sphene structure according to claim 1, wherein the host component comprises an isotype mixed phase of CaTiSiO5 and CaSnSiO5 of the formula CaTi1 xSnxSiO5 in which x 0.01 to 99.9.
 6. Synthetic mixed phases of sphene structure according to claim 1 wherein the guest component or components are present in an amount of about 0.1 to 50 percent by weight. 